U.S. patent application number 13/294166 was filed with the patent office on 2013-04-04 for image generating device with improved illumination efficiency.
The applicant listed for this patent is Chueh-Pin Ko. Invention is credited to Chueh-Pin Ko.
Application Number | 20130083293 13/294166 |
Document ID | / |
Family ID | 45315542 |
Filed Date | 2013-04-04 |
United States Patent
Application |
20130083293 |
Kind Code |
A1 |
Ko; Chueh-Pin |
April 4, 2013 |
IMAGE GENERATING DEVICE WITH IMPROVED ILLUMINATION EFFICIENCY
Abstract
An image generating device includes a light source, a light
filtering element, a light conversion element, and an image
generating element. The light source is for generating visible
light. The light filtering element is disposed on a light path of
the visible light. The light filtering element includes a plurality
of light filtering blocks, and each of the light filtering blocks
is for allowing light with wavelength within a predetermined range
to pass through. The light conversion element is disposed on the
light path. The light conversion element includes a first quantum
dot layer for converting light with wavelength below a first
wavelength to light with the first wavelength. The image generating
element is for generating images according to light passed through
the light filtering element and the light conversion element.
Inventors: |
Ko; Chueh-Pin; (New Taipei
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ko; Chueh-Pin |
New Taipei City |
|
TW |
|
|
Family ID: |
45315542 |
Appl. No.: |
13/294166 |
Filed: |
November 10, 2011 |
Current U.S.
Class: |
353/20 ;
362/293 |
Current CPC
Class: |
B82Y 20/00 20130101;
G02B 27/1053 20130101; G02B 5/207 20130101; G02B 26/008 20130101;
G02B 2207/101 20130101; G02B 27/1033 20130101; H04N 9/3114
20130101; H04N 9/3158 20130101 |
Class at
Publication: |
353/20 ;
362/293 |
International
Class: |
G03B 21/14 20060101
G03B021/14; F21V 9/00 20060101 F21V009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 3, 2011 |
TW |
100135731 |
Claims
1. An image generating device with improved illumination efficiency
comprising: a light source for generating visible light; a light
filtering element disposed on a light path of the visible light,
the light filtering element comprising a plurality of light
filtering blocks, each of the light filtering blocks being utilized
for allowing light with wavelength within a predetermined range to
pass through; a light conversion element disposed on the light path
of the visible light, the light conversion element comprising a
first quantum dot layer for converting light with wavelengths below
a first wavelength to light with the first wavelength; and an image
generating element for generating images according to light passed
through the light filtering element and the light conversion
element.
2. The image generating device of claim 1, wherein the light
filtering element further comprises a light transmission block for
allowing the visible light to pass through, and the first quantum
dot layer is arranged at a position corresponding to the light
transmission block.
3. The image generating device of claim 2, wherein the light with
the first wavelength is red light.
4. The image generating device of claim 1, wherein the plurality of
light filtering blocks comprises a first light filtering block for
allowing light with wavelength within a first predetermined range
to pass through, a second light filtering block for allowing light
with wavelength within a second predetermined range to pass
through, and a third light filtering block for allowing light with
wavelength within a third predetermined range to pass through, the
first quantum dot layer is arranged at a position corresponding to
the first light filtering block, and the first wavelength is within
the first predetermined range.
5. The image generating device of claim 4, wherein the light
conversion element further comprises a second quantum dot layer for
converting light with wavelengths below a second wavelength to
light with the second wavelength, the second quantum dot layer is
arranged at a position corresponding to the second light filtering
block, and the second wavelength is within the second predetermined
range.
6. The image generating device of claim 5, wherein the light
conversion element further comprises a third quantum dot layer for
converting light with wavelengths below a third wavelength to light
with the third wavelength, the third quantum dot layer is arranged
at a position corresponding to the third light filtering block, the
third wavelength is within the third predetermined range, and the
second wavelength is greater than the third wavelength.
7. The image generating device of claim 5, wherein a particle size
of a quantum dot of the first quantum dot layer is different from a
particle size of a quantum dot of the second quantum dot layer.
8. The image generating device of claim 4, wherein the first
predetermined range is between the first wavelength and zero.
9. The image generating device of claim 4, wherein the first
predetermined range is between the first wavelength and a second
wavelength.
10. The image generating device of claim 1, wherein the light
conversion element is disposed on a surface of the light filtering
element.
11. The image generating device of claim 1, wherein the light
conversion element and the light filtering element rotate
synchronously.
12. The projector of claim 1, further comprising a projection
module for projecting the images generated by the image generating
element.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image generating device,
and more particularly, to an image generating device utilizing
quantum dots for improving illumination efficiency.
[0003] 2. Description of the Prior Art
[0004] Please refer to FIG. 1. FIG. 1 is a diagram showing a
projector 100 of the prior art. As shown in FIG. 1, the projector
100 comprises a light source 110, a color wheel 120, an optical
module 130, an image generating element 140, and a projection
module 150. The light source 110 is for generating visible light
with a continuous spectrum. The color wheel 120 is disposed on a
light path P of the visible light. The color wheel 120 comprises a
plurality of light filtering blocks, such as a red light filtering
block, a green light filtering block, and a blue light filtering
block. The red light filtering block is for allowing light with
wavelengths of red light (such as 600 nanometers to 700 nanometers)
to pass through. The green light filtering block is for allowing
light with wavelengths of green light (such as 500 nanometers to
600 nanometers) to pass through. The blue light filtering block is
for allowing light with wavelengths of blue light (such as 400
nanometers to 500 nanometers) to pass through. The color wheel 120
rotates at a predetermined speed for allowing the red light, the
green light, and the blue light to pass through respectively
according to a predetermined time sequence. The optical module 130
is for guiding light transmitted from the color wheel 120 to the
image generating element 140. The image generating element 140 then
generates red images, green images, and blue images according to
the red light, the green light, and the blue light transmitted from
the optical module 130 respectively. The projection module 150
projects the red images, the green images and the blue images
generated by the image generating element 140 onto a screen for
forming complete images. The image generating element 140 is
generally a digital micromirror device (DMD). The digital
micromirror device comprises an array of micromirrors for
reflecting the light to generate images according to image
data.
[0005] However, according to the above arrangement, when the light
filtering block of the color wheel 120 allows light with wavelength
within the predetermined range to pass through, other light with
wavelength outside the predetermined range of the light filtering
block is filtered out, such that the light with wavelength outside
the predetermined range of the light filtering block cannot be
utilized for generating images. Therefore, the visible light
generated by the light source of the projector of the prior art is
not utilized efficiently.
SUMMARY OF THE INVENTION
[0006] The present invention provides an image generating device
with improved illumination efficiency. The image generating device
comprises a light source, a light filtering element, a light
conversion element, and an image generating element. The light
source is for generating visible light. The light filtering element
is disposed on a light path of the visible light. The light
filtering element comprises a plurality of light filtering blocks,
and each of the light filtering blocks is for allowing light with
wavelength within a predetermined range to pass through. The light
conversion element is disposed on the light path. The light
conversion element comprises a first quantum dot layer for
converting light with wavelength below a first wavelength to light
with the first wavelength. The image generating element is for
generating images according to light passed through the light
filtering element and the light conversion element.
[0007] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagram showing a projector of the prior
art.
[0009] FIG. 2 is a diagram showing a projector of the present
invention.
[0010] FIG. 3 is a diagram showing a first embodiment of a
combination of a color wheel and a light conversion element of FIG.
2.
[0011] FIG. 4 is a diagram showing a second embodiment of a
combination of the color wheel and the light conversion element of
FIG. 2.
[0012] FIG. 5 is a diagram showing a third embodiment of a
combination of the color wheel and the light conversion element of
FIG. 2.
[0013] FIG. 6 is a diagram showing a forth embodiment of a
combination of the color wheel and the light conversion element of
FIG. 2.
DETAILED DESCRIPTION
[0014] The quantum dot is a nanoscale semiconductor material, which
can be an element of semiconductor material (such as Si, Ge), or a
compound of semiconductor material (such as CdSe or CdS). A
particle diameter of the quantum dot is less than 100 nanometers.
The quantum dot can absorb light with wavelengths below a
predetermined wavelength according to the particle size, and
convert the light with wavelengths below the predetermined
wavelength to light with the predetermined wavelength. For example,
when the particle diameter of a CdSe quantum dot is 2.1 nanometers,
the CdSe quantum dot absorbs light with wavelengths below a blue
light wavelength, and converts the light with wavelengths below the
blue light wavelength to the blue light. When the particle diameter
of the CdSe quantum dot is 5 nanometers, the CdSe quantum dot
absorbs light with wavelengths below a green light wavelength, and
converts the light with wavelengths below the green light
wavelength to the green light. When the particle diameter of the
CdSe quantum dot is close to 10 nanometers, the CdSe quantum dot
absorbs light with wavelengths below a red light wavelength, and
converts the light with wavelengths below the red light wavelength
to the red light. In addition, a structure of the quantum dot can
be composed of more than one semiconductor material. A shell of the
quantum dot and a core of the quantum dot can be made of different
materials respectively. The present invention utilizes quantum dots
with different particle sizes to generate light with different
colors for improving illumination efficiency of a projector.
[0015] Please refer to FIG. 2 and FIG. 3. FIG. 2 is a diagram
showing a projector 200 of the present invention. FIG. 3 is a
diagram showing a first embodiment of a combination of a color
wheel and a light conversion element of FIG. 2. The projector 200
of present invention comprises a light source 210, a color wheel
220, a light conversion element 260, an optical module 230, an
image generating element 240, and a projection module 250. The
light source 210 is for generating visible light with a continuous
spectrum (the light source 210 may also generate non-visible light,
such as UV light). The color wheel 220 is disposed on a light path
P of the visible light. The color wheel 220 comprises a first light
filtering block 222, a second light filtering block 224, and a
third light filtering block 226. The first light filtering block
222 is for allowing light with wavelengths of red light (such as
600 nanometers to 700 nanometers) to pass through. The second light
filtering block 224 is for allowing light with wavelengths of green
light (such as 500 nanometers to 600 nanometers) to pass through.
The third light filtering block 226 is for allowing light with
wavelengths of blue light (such as 400 nanometers to 500
nanometers) to pass through. In the above embodiment of the
projector of the present invention, the color wheel 220 works as a
light filtering element for filtering light. In other embodiments
of image generating devices of the present invention, the light
filtering element is not limited to a color wheel. The light
conversion element 260 is disposed between the light source 210 and
the color wheel 220 along the light path P of the visible light. A
light conversion element 260A comprises a quantum dot layer 262A.
Quantum dots on the quantum dot layer 262A are for converting light
with wavelengths below a wavelength of red light (such as 650
nanometers) to the red light with wavelength of 650 nanometers (or
around 650 nanometers). The quantum dot layer 262A is disposed on a
position corresponding to the first light filtering block 222. The
light conversion element 260 can be disposed on a surface of the
color wheel 220 to rotate with the color wheel 220, or the light
conversion element 260 can be an independent element, which is
rotated synchronously with the color wheel 220. The color wheel 220
rotates at a predetermined speed for allowing the red (R) light,
the green (G) light, and the blue (B) light to pass through
respectively according to a predetermined time sequence. The
optical module 230 is for guiding light transmitted from the color
wheel 220 to the image generating element 240. The image generating
element 240 (such as a digital micromirror device) then generates
red images, green images, and blue images according to the red
light, the green light, and the blue light transmitted from the
optical module 230 respectively. The projection module 250 projects
the red images, the green images and the blue images generated by
the image generating element 240 onto a screen for forming complete
images.
[0016] According to the above arrangement, when the visible light
generated by the light source 210 passes through the quantum dot
layer 262A, light with wavelengths below 650 nanometers is
converted to the red light with wavelength of 650 nanometers (or
around 650 nanometers) and then passes through the first light
filtering block 222. That is, energy of the red light passed
through the color wheel 220 comprises energy of the original red,
green, and blue light, and even comprises energy of other light
(such as UV light generated by the light source). Therefore,
brightness of the red light passed through the color wheel 220 is
increased significantly.
[0017] In addition, the first light filtering block 222 can also
allow light with wavelengths below 700 nanometers to pass through,
or the first light filtering block 222 can be replaced by a light
transmission block which allows most of the visible light to pass
through. The quantum dot layer 262A of the light conversion element
260A can also be utilized for generating the green light or blue
light. When the quantum dot layer 262A is utilized for generating
the green light, the quantum dot layer 262A is disposed on a
position corresponding to the second light filtering block 224,
which allows light with wavelengths below 600 nanometers to pass
through. According to such arrangement, energy of the green light
passed through the color wheel 220 comprises energy of the original
green light and blue light, and even comprises energy of other
non-visible light. Therefore, brightness of the green light passed
through the color wheel 220 is increased significantly. When the
quantum dot layer 262A is utilized for generating the blue light,
the quantum dot layer 262A is disposed on a position corresponding
to the third light filtering block 226, which allows light with
wavelengths below 500 nanometers to pass through. According to such
arrangement, energy of the blue light passed through the color
wheel 220 comprises energy of the original blue light and other
non-visible light. Therefore, brightness of the blue light passed
through the color wheel 220 is increased significantly.
[0018] Please refer to FIG. 4, and refer to FIG. 2 as well. FIG. 4
is a diagram showing a second embodiment of a combination of the
color wheel and the light conversion element of FIG. 2. As shown in
FIG. 4, a light conversion element 260B comprises a first quantum
dot layer 262B and a second quantum dot layer 264B. The first
quantum dot layer 262B is disposed on a position corresponding to
the first light filtering block 222. The first quantum dot layer
262B is for converting the light with wavelengths below a
wavelength of red light (such as 650 nanometers) to the red light
with wavelength of 650 nanometers (or around 650 nanometers). The
second quantum dot layer 264B is disposed on a position
corresponding to the second light filtering block 224. The second
quantum dot layer 264B is for converting the light with wavelengths
below a wavelength of green light (such as 550 nanometers) to the
green light with wavelength of 550 nanometers (or around 550
nanometers). The first light filtering block 222 of the color wheel
220 is for allowing the light with the wavelengths of red light
(such as 600 nanometers to 700 nanometers) to pass through, or for
allowing the light with wavelengths below 700 nanometers to pass
through. The second light filtering block 224 of the color wheel
220 is for allowing the light with the wavelengths of green light
(such as 500 nanometers to 600 nanometers) to pass through, or for
allowing the light with wavelengths below 600 nanometers to pass
through. The third light filtering block 226 of the color wheel 220
is for allowing the light with the wavelengths of blue light (such
as 400 nanometers to 500 nanometers) to pass through, or for
allowing the light with wavelengths below 500 nanometers to pass
through.
[0019] According to the above arrangement, when the visible light
generated by the light source 210 passes through the first quantum
dot layer 262B, the light with wavelengths below 650 nanometers is
converted to the red light with wavelength of 650 nanometers (or
around 650 nanometers) and then passes through the first light
filtering block 222. That is, energy of the red light passed
through the color wheel 220 comprises energy of the original red,
green, and blue light, and even comprises energy of other light.
Therefore, the brightness of the red light passed through the color
wheel 220 is increased significantly. When the visible light
generated by the light source 210 passes through the second quantum
dot layer 264B, the light with wavelength below 550 nanometers is
converted to the green light with wavelength of 550 nanometers (or
around 550 nanometers) and then passes through the second light
filtering block 224. That is, energy of the green light passed
through the color wheel 220 comprises energy of the original green
and blue light, and even comprises energy of other light.
Therefore, the brightness of the green light passed through the
color wheel 220 is increased significantly.
[0020] Similarly, the first quantum dot layer 262B and the second
quantum dot layer 264B of FIG. 4 can be a combination to generate
the red light and the blue light, or a combination to generate the
green light and the blue light. When the first quantum dot layer
262B and the second quantum dot layer 264B are utilized to generate
other combinations of color light, the first quantum dot layer 262B
and the second quantum dot layer 264B should be matched with the
corresponding light filtering blocks.
[0021] Please refer to FIG. 5, and refer to FIG. 2 as well. FIG. 5
is a diagram showing a third embodiment of a combination of the
color wheel and the light conversion element of FIG. 2. As shown in
FIG. 5, the light conversion element comprises a first quantum dot
layer 262C, a second quantum dot layer 264C, and a third quantum
dot layer 266C for generating the red light (such as the red light
with wavelength of 650 nanometers), the green light (such as the
green light with wavelength of 550 nanometers), and the blue light
(such as the blue light with wavelength of 450 nanometers)
respectively.
[0022] According to the above arrangement, when the visible light
generated by the light source 210 passes through the first quantum
dot layer 262C, the light with wavelengths below 650 nanometers is
converted to the red light with wavelength of 650 nanometers (or
around 650 nanometers) and then passes through the first light
filtering block 222. That is, energy of the red light passed
through the color wheel 220 comprises energy of the original red,
green, and blue light, and even comprises energy of other light.
Therefore, the brightness of the red light passed through the color
wheel 220 is increased significantly. When the visible light
generated by the light source 210 passes through the second quantum
dot layer 264C, the light with wavelengths below 550 nanometers is
converted to the green light with wavelength of 550 nanometers (or
around 550 nanometers) and then passes through the second light
filtering block 224. That is, energy of the green light passed
through the color wheel 220 comprises energy of the original green
and blue light, and even comprises energy of other light.
Therefore, the brightness of the green light passed through the
color wheel 220 is increased significantly. When the visible light
generated by the light source 210 passes through the third quantum
dot layer 266C, the light with wavelengths below 450 nanometers is
converted to the blue light with wavelength of 450 nanometers (or
around 450 nanometers) and then passes through the third light
filtering block 226. That is, energy of the blue light passed
through the color wheel 220 comprises energy of the original blue
light and light with wavelengths below the blue light wavelength.
Therefore, the brightness of the blue light passed through the
color wheel 220 is also increased.
[0023] Please refer to FIG. 6, and refer to FIG. 2 as well. FIG. 6
is a diagram showing a fourth embodiment of a combination of the
color wheel and the light conversion element of FIG. 2. As shown in
FIG. 6, a light conversion element 260D further comprises a fourth
quantum dot layer 268D for generating light with a fourth color,
such as yellow Y. The color wheel 220D further comprises a
corresponding fourth light filtering block 228D, such that images
generated by the projector can be more colorful.
[0024] The above embodiments are only for illustrating operation of
the projector of the present invention. The quantity and the colors
of the light filtering blocks of the color wheel and the quantity
and the colors of the quantum dot layers of the light conversion
element can be determined according to design requirements.
[0025] Moreover, in the above embodiments, the light conversion
element 260 is disposed between the light source 210 and the color
wheel 220 along the light path P of the visible light. However, in
other embodiments, the color wheel can be disposed between the
light source and the light conversion element along the light path
of the visible light.
[0026] In addition, the present invention can also be utilized in
other types of image generating devices, such as a rear projection
television or a liquid crystal display device. The image generating
device of the present invention can utilize the light conversion
element and the light filtering element to generate light with
different colors, and further generates color images.
[0027] In contrast to the prior art, the image generating device of
the present invention utilizes quantum dots to absorb light with
different wavelengths and converts the light to light with a
predetermined wavelength, such that the illumination efficiency of
each color is increased, and the brightness of images is increased
as well. Furthermore, wavelength of each color light generated by
the quantum dots is fixed, such that color purity and color gamut
are improved, and the quality of images is further improved.
[0028] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *